If your dog is walking off-lead when other people are nearby, he should be right next to you, within a few inches. The animal should never leave your side unless you give him the verbal go-ahead, and you should never do that if there are people nearby, unless you first check with them and make sure that they want to interact with the dog. Likewise, your dog should not approach other dogs or any other living creature without your permission.

If you are out in the open with absolutely no one around, you may let the dog wander a little further away. But even then, you must keep your dog nearby and under your vigilent supervision at all times. Point of clarification: "Nearby" doesn't mean running off in the distance. If there are people in sight, your dog should be within a few yards of you. If there are people close enough to feel threatened by his presence, he should be within inches of you.

If you pass someone on the sidewalk or in other close spaces, you should move your dog to the opposite side from where the other person is walking. Your dog should certainly not be out in front of you. Rather, he should be at you side, positioned so that your body is between him and the person you are passing.

As a matter of courtesy, when you approach someone with your dog off-lead, you should issue your dog a command in order to demonstrate your awareness of their presence, and also to reassure them that you are mindful of your responsibilites and that you have your dog under control. It can be as simple as commanding the dog to move from where he is, on your one side, over to the side of your body which is furthest from the stranger. Or, you might just want to stop walking and come to a halt for a second, so the stranger can see that the dog comes to a halt and sits when you stop walking, which is behavior consistent with a well-trained, under control dog.

It is a matter of civilized decorum. You should always reassure those you approach by commanding your dog so that you may demonstrate your competence and intent. And your dog should never approach anyone uninvited.

As a matter of habit, the more closely people approach, the more closely your dog should gather by your side.

Always have your identification decal prominently displayed.

Always have the leash with you. Always!
Even if you and your dog are long-time veterans of off-lead travel:
Never leave the house without the lead.
Never leave the house without the lead.
Never leave the house without the lead.